Database security is essential for protecting sensitive data from unauthorized access, breaches, and compliance violations. Modern database security combines multiple defensive layers including SQL injection prevention, encryption at rest and in transit, authentication and authorization controls, and audit logging. This cheat sheet covers industry-standard security practices spanning relational databases (SQL Server, PostgreSQL, Oracle, MySQL), cloud platforms (AWS RDS, Azure SQL, Google Cloud SQL), and compliance frameworks (GDPR, CCPA, HIPAA, PCI-DSS). One non-obvious insight: defense in depth requires implementing security at every layer—network, database engine, schema objects, and application code—because a single compromised layer can expose your entire data estate.
What This Cheat Sheet Covers
This topic spans 14 focused tables and 94 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: SQL Injection Prevention Techniques
SQL injection remains one of the most damaging and stubbornly common database attacks, and nearly all of it traces back to mixing user input into query text. The defenses here are ranked the way OWASP ranks them—parameterized queries first, allow-list validation for the cases parameters can't cover, and escaping only as a last resort—with least-privilege accounts as the safety net that limits the blast radius when something slips through.
| Technique | Example | Description |
|---|---|---|
Java: PreparedStatement ps = conn.prepareStatement("SELECT * FROM users WHERE id = ?"); ps.setInt(1, userId); | • Separates SQL code from data by using placeholders for user input • database engine treats parameters as data only, preventing injection regardless of malicious content | |
SQL Server: CREATE PROCEDURE GetUser @UserId INT AS SELECT * FROM Users WHERE UserId = @UserId | • Encapsulates query logic in precompiled database routines • must use parameters internally to be safe, not dynamic SQL concatenation | |
Hibernate: Query q = session.createQuery("FROM User WHERE id = :userId"); q.setParameter("userId", userId); | • Object-Relational Mapping tools auto-generate parameterized queries • still vulnerable if using raw SQL or string concatenation in criteria |